/* ----------------------------------------------------------------------
* Copyright (C) 2010 ARM Limited. All rights reserved.
*
* $Date:        15. February 2012
* $Revision: 	V1.1.0
*
* Project: 	    CMSIS DSP Library
* Title:	    arm_mat_mult_q15.c
*
* Description:	 Q15 matrix multiplication.
*
* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
*
* Version 1.1.0 2012/02/15
*    Updated with more optimizations, bug fixes and minor API changes.
*
* Version 1.0.10 2011/7/15
*    Big Endian support added and Merged M0 and M3/M4 Source code.
*
* Version 1.0.3 2010/11/29
*    Re-organized the CMSIS folders and updated documentation.
*
* Version 1.0.2 2010/11/11
*    Documentation updated.
*
* Version 1.0.1 2010/10/05
*    Production release and review comments incorporated.
*
* Version 1.0.0 2010/09/20
*    Production release and review comments incorporated.
*
* Version 0.0.5  2010/04/26
*    incorporated review comments and updated with latest CMSIS layer
*
* Version 0.0.3  2010/03/10
*    Initial version
* -------------------------------------------------------------------- */

#include "arm_math.h"

/**
 * @ingroup groupMatrix
 */

/**
 * @addtogroup MatrixMult
 * @{
 */


/**
 * @brief Q15 matrix multiplication
 * @param[in]       *pSrcA points to the first input matrix structure
 * @param[in]       *pSrcB points to the second input matrix structure
 * @param[out]      *pDst points to output matrix structure
 * @param[in]		*pState points to the array for storing intermediate results
 * @return     		The function returns either
 * <code>ARM_MATH_SIZE_MISMATCH</code> or <code>ARM_MATH_SUCCESS</code> based on the outcome of size checking.
 *
 * @details
 * <b>Scaling and Overflow Behavior:</b>
 *
 * \par
 * The function is implemented using a 64-bit internal accumulator. The inputs to the
 * multiplications are in 1.15 format and multiplications yield a 2.30 result.
 * The 2.30 intermediate
 * results are accumulated in a 64-bit accumulator in 34.30 format. This approach
 * provides 33 guard bits and there is no risk of overflow. The 34.30 result is then
 * truncated to 34.15 format by discarding the low 15 bits and then saturated to
 * 1.15 format.
 *
 * \par
 * Refer to <code>arm_mat_mult_fast_q15()</code> for a faster but less precise version of this function for Cortex-M3 and Cortex-M4.
 *
 */

arm_status arm_mat_mult_q15(
    const arm_matrix_instance_q15* pSrcA,
    const arm_matrix_instance_q15* pSrcB,
    arm_matrix_instance_q15* pDst,
    q15_t* pState)
{
	q63_t sum;                                     /* accumulator */

#ifndef ARM_MATH_CM0

	/* Run the below code for Cortex-M4 and Cortex-M3 */

	q15_t* pSrcBT = pState;                        /* input data matrix pointer for transpose */
	q15_t* pInA = pSrcA->pData;                    /* input data matrix pointer A of Q15 type */
	q15_t* pInB = pSrcB->pData;                    /* input data matrix pointer B of Q15 type */
	q15_t* px;                                     /* Temporary output data matrix pointer */
	uint16_t numRowsA = pSrcA->numRows;            /* number of rows of input matrix A    */
	uint16_t numColsB = pSrcB->numCols;            /* number of columns of input matrix B */
	uint16_t numColsA = pSrcA->numCols;            /* number of columns of input matrix A */
	uint16_t numRowsB = pSrcB->numRows;            /* number of rows of input matrix A    */
	uint16_t col, i = 0u, row = numRowsB, colCnt;  /* loop counters */
	arm_status status;                             /* status of matrix multiplication */

#ifndef UNALIGNED_SUPPORT_DISABLE

	q31_t in;                                      /* Temporary variable to hold the input value */
	q31_t pSourceA1, pSourceB1, pSourceA2, pSourceB2;

#else

	q15_t in;                                      /* Temporary variable to hold the input value */
	q15_t inA1, inB1, inA2, inB2;

#endif	/*	#ifndef UNALIGNED_SUPPORT_DISABLE	*/

#ifdef ARM_MATH_MATRIX_CHECK

	/* Check for matrix mismatch condition */
	if((pSrcA->numCols != pSrcB->numRows) ||
	        (pSrcA->numRows != pDst->numRows) || (pSrcB->numCols != pDst->numCols)) {
		/* Set status as ARM_MATH_SIZE_MISMATCH */
		status = ARM_MATH_SIZE_MISMATCH;
	} else
#endif /*    #ifdef ARM_MATH_MATRIX_CHECK    */
	{
		/* Matrix transpose */
		do {
			/* Apply loop unrolling and exchange the columns with row elements */
			col = numColsB >> 2;

			/* The pointer px is set to starting address of the column being processed */
			px = pSrcBT + i;

			/* First part of the processing with loop unrolling.  Compute 4 outputs at a time.
			 ** a second loop below computes the remaining 1 to 3 samples. */
			while(col > 0u) {
#ifndef UNALIGNED_SUPPORT_DISABLE

				/* Read two elements from the row */
				in = *__SIMD32(pInB)++;

				/* Unpack and store one element in the destination */
#ifndef ARM_MATH_BIG_ENDIAN

				*px = (q15_t) in;

#else

				*px = (q15_t)((in & (q31_t) 0xffff0000) >> 16);

#endif /*    #ifndef ARM_MATH_BIG_ENDIAN    */

				/* Update the pointer px to point to the next row of the transposed matrix */
				px += numRowsB;

				/* Unpack and store the second element in the destination */
#ifndef ARM_MATH_BIG_ENDIAN

				*px = (q15_t)((in & (q31_t) 0xffff0000) >> 16);

#else

				*px = (q15_t) in;

#endif /*    #ifndef ARM_MATH_BIG_ENDIAN    */

				/* Update the pointer px to point to the next row of the transposed matrix */
				px += numRowsB;

				/* Read two elements from the row */
				in = *__SIMD32(pInB)++;

				/* Unpack and store one element in the destination */
#ifndef ARM_MATH_BIG_ENDIAN

				*px = (q15_t) in;

#else

				*px = (q15_t)((in & (q31_t) 0xffff0000) >> 16);

#endif /*    #ifndef ARM_MATH_BIG_ENDIAN    */

				/* Update the pointer px to point to the next row of the transposed matrix */
				px += numRowsB;

				/* Unpack and store the second element in the destination */

#ifndef ARM_MATH_BIG_ENDIAN

				*px = (q15_t)((in & (q31_t) 0xffff0000) >> 16);

#else

				*px = (q15_t) in;

#endif /*    #ifndef ARM_MATH_BIG_ENDIAN    */

				/* Update the pointer px to point to the next row of the transposed matrix */
				px += numRowsB;

#else

				/* Read one element from the row */
				in = *pInB++;

				/* Store one element in the destination */
				*px = in;

				/* Update the pointer px to point to the next row of the transposed matrix */
				px += numRowsB;

				/* Read one element from the row */
				in = *pInB++;

				/* Store one element in the destination */
				*px = in;

				/* Update the pointer px to point to the next row of the transposed matrix */
				px += numRowsB;

				/* Read one element from the row */
				in = *pInB++;

				/* Store one element in the destination */
				*px = in;

				/* Update the pointer px to point to the next row of the transposed matrix */
				px += numRowsB;

				/* Read one element from the row */
				in = *pInB++;

				/* Store one element in the destination */
				*px = in;

				/* Update the pointer px to point to the next row of the transposed matrix */
				px += numRowsB;

#endif	/*	#ifndef UNALIGNED_SUPPORT_DISABLE	*/

				/* Decrement the column loop counter */
				col--;
			}

			/* If the columns of pSrcB is not a multiple of 4, compute any remaining output samples here.
			 ** No loop unrolling is used. */
			col = numColsB % 0x4u;

			while(col > 0u) {
				/* Read and store the input element in the destination */
				*px = *pInB++;

				/* Update the pointer px to point to the next row of the transposed matrix */
				px += numRowsB;

				/* Decrement the column loop counter */
				col--;
			}

			i++;

			/* Decrement the row loop counter */
			row--;

		} while(row > 0u);

		/* Reset the variables for the usage in the following multiplication process */
		row = numRowsA;
		i = 0u;
		px = pDst->pData;

		/* The following loop performs the dot-product of each row in pSrcA with each column in pSrcB */
		/* row loop */
		do {
			/* For every row wise process, the column loop counter is to be initiated */
			col = numColsB;

			/* For every row wise process, the pIn2 pointer is set
			 ** to the starting address of the transposed pSrcB data */
			pInB = pSrcBT;

			/* column loop */
			do {
				/* Set the variable sum, that acts as accumulator, to zero */
				sum = 0;

				/* Apply loop unrolling and compute 2 MACs simultaneously. */
				colCnt = numColsA >> 2;

				/* Initiate the pointer pIn1 to point to the starting address of the column being processed */
				pInA = pSrcA->pData + i;


				/* matrix multiplication */
				while(colCnt > 0u) {
					/* c(m,n) = a(1,1)*b(1,1) + a(1,2) * b(2,1) + .... + a(m,p)*b(p,n) */
#ifndef UNALIGNED_SUPPORT_DISABLE

					/* read real and imag values from pSrcA and pSrcB buffer */
					pSourceA1 = *__SIMD32(pInA)++;
					pSourceB1 = *__SIMD32(pInB)++;

					pSourceA2 = *__SIMD32(pInA)++;
					pSourceB2 = *__SIMD32(pInB)++;

					/* Multiply and Accumlates */
					sum = __SMLALD(pSourceA1, pSourceB1, sum);
					sum = __SMLALD(pSourceA2, pSourceB2, sum);

#else
					/* read real and imag values from pSrcA and pSrcB buffer */
					inA1 = *pInA++;
					inB1 = *pInB++;
					inA2 = *pInA++;
					/* Multiply and Accumlates */
					sum += inA1 * inB1;
					inB2 = *pInB++;

					inA1 = *pInA++;
					inB1 = *pInB++;
					/* Multiply and Accumlates */
					sum += inA2 * inB2;
					inA2 = *pInA++;
					inB2 = *pInB++;

					/* Multiply and Accumlates */
					sum += inA1 * inB1;
					sum += inA2 * inB2;

#endif	/*	#ifndef UNALIGNED_SUPPORT_DISABLE	*/

					/* Decrement the loop counter */
					colCnt--;
				}

				/* process remaining column samples */
				colCnt = numColsA & 3u;

				while(colCnt > 0u) {
					/* c(m,n) = a(1,1)*b(1,1) + a(1,2) * b(2,1) + .... + a(m,p)*b(p,n) */
					sum += *pInA++ * *pInB++;

					/* Decrement the loop counter */
					colCnt--;
				}

				/* Saturate and store the result in the destination buffer */
				*px = (q15_t)(__SSAT((sum >> 15), 16));
				px++;

				/* Decrement the column loop counter */
				col--;

			} while(col > 0u);

			i = i + numColsA;

			/* Decrement the row loop counter */
			row--;

		} while(row > 0u);

#else

	/* Run the below code for Cortex-M0 */

	q15_t* pIn1 = pSrcA->pData;                    /* input data matrix pointer A */
	q15_t* pIn2 = pSrcB->pData;                    /* input data matrix pointer B */
	q15_t* pInA = pSrcA->pData;                    /* input data matrix pointer A of Q15 type */
	q15_t* pInB = pSrcB->pData;                    /* input data matrix pointer B of Q15 type */
	q15_t* pOut = pDst->pData;                     /* output data matrix pointer */
	q15_t* px;                                     /* Temporary output data matrix pointer */
	uint16_t numColsB = pSrcB->numCols;            /* number of columns of input matrix B */
	uint16_t numColsA = pSrcA->numCols;            /* number of columns of input matrix A */
	uint16_t numRowsA = pSrcA->numRows;            /* number of rows of input matrix A    */
	uint16_t col, i = 0u, row = numRowsA, colCnt;  /* loop counters */
	arm_status status;                             /* status of matrix multiplication */

#ifdef ARM_MATH_MATRIX_CHECK

	/* Check for matrix mismatch condition */
	if((pSrcA->numCols != pSrcB->numRows) ||
	        (pSrcA->numRows != pDst->numRows) || (pSrcB->numCols != pDst->numCols)) {
		/* Set status as ARM_MATH_SIZE_MISMATCH */
		status = ARM_MATH_SIZE_MISMATCH;
	} else
#endif /*    #ifdef ARM_MATH_MATRIX_CHECK    */

	{
		/* The following loop performs the dot-product of each row in pSrcA with each column in pSrcB */
		/* row loop */
		do {
			/* Output pointer is set to starting address of the row being processed */
			px = pOut + i;

			/* For every row wise process, the column loop counter is to be initiated */
			col = numColsB;

			/* For every row wise process, the pIn2 pointer is set
			 ** to the starting address of the pSrcB data */
			pIn2 = pSrcB->pData;

			/* column loop */
			do {
				/* Set the variable sum, that acts as accumulator, to zero */
				sum = 0;

				/* Initiate the pointer pIn1 to point to the starting address of pSrcA */
				pIn1 = pInA;

				/* Matrix A columns number of MAC operations are to be performed */
				colCnt = numColsA;

				/* matrix multiplication */
				while(colCnt > 0u) {
					/* c(m,n) = a(1,1)*b(1,1) + a(1,2) * b(2,1) + .... + a(m,p)*b(p,n) */
					/* Perform the multiply-accumulates */
					sum += (q31_t) * pIn1++ * *pIn2;
					pIn2 += numColsB;

					/* Decrement the loop counter */
					colCnt--;
				}

				/* Convert the result from 34.30 to 1.15 format and store the saturated value in destination buffer */
				/* Saturate and store the result in the destination buffer */
				*px++ = (q15_t) __SSAT((sum >> 15), 16);

				/* Decrement the column loop counter */
				col--;

				/* Update the pointer pIn2 to point to the  starting address of the next column */
				pIn2 = pInB + (numColsB - col);

			} while(col > 0u);

			/* Update the pointer pSrcA to point to the  starting address of the next row */
			i = i + numColsB;
			pInA = pInA + numColsA;

			/* Decrement the row loop counter */
			row--;

		} while(row > 0u);

#endif /* #ifndef ARM_MATH_CM0 */
		/* set status as ARM_MATH_SUCCESS */
		status = ARM_MATH_SUCCESS;
	}

	/* Return to application */
	return (status);
}

/**
 * @} end of MatrixMult group
 */
